WinRAR Flaw Exploited by Russia-Aligned Groups to Deploy Stealers in Ukraine
Jun 09, 2026
Vulnerability / Cyber Espionage
Two Russia-aligned cyber attack campaigns have continued to exploit a security flaw in WinRAR to target Ukrainian organisations, almost a year after patches for the vulnerability were released. The activity has been attributed by Trend Micro to Earth Dahu (aka Gamaredon) and SHADOW-EARTH-066 (aka UAC-0226). It involves the exploitation of CVE-2025-8088 , a path traversal flaw that allows an attacker to write files outside the extraction directory via NTFS Alternate Data Streams (ADS). It was patched by WinRAR in July 2025. The findings show "how unmanaged software keeps an exploited entry point open long after the fix ships," Trend Micro researchers Hiroyuki Kakara and Feike Hacquebord said in an analysis published Monday. The WinRAR exploit chain exploited by SHADOW-EARTH-066 is a departure from Excel macro droppers previously used by the threat actor to deliver an information stealer called GIFTEDCROOK. The latest iteration makes use of crafted RAR archives featur...
